# Multiple Room Ventilation (Stosslueften) **URL:** \ **Category:** Flows\ **Created:** [December 15, 2025, 9:38am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943 "2025-12-15T09:38:39Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Andreas\_Martin](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/andreas_martin/32/121367_2.png) [@Andreas\_Martin](https://community.homey.app/u/Andreas_Martin)\ **Post date:** [December 15, 2025, 9:38am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/1 "2025-12-15T09:38:40Z")
I want to establish a best practice flow for Stosslueften (german which means ventilating more than one room by fully opening windows in multiple rooms and the connecting doors are open as well). WHAT IS NEEDED? - smart thermostat which turns on/off the heating - some kind of sensors - (wind sensor in the hallway would be “best” but ugly and problematic with children) - contact sensors on the windows and connecting doors - a flow to rule them all 🙂 I HAVE NOT found the perfect solution just yet. So I’m looking for advice. I have defined a variable “Stosslueften” YES/NO. When all windows are closed it is set to NO: If multiple windows are open it is set to YES: (here I struggle most since there are almost unlimted combinations of windows which can be opened. In a perfect world we open always the same windows but most of the time just some of the windows. This makes it complicated for me. We have 8 rooms with windows. The rooms have between 1 and 4 windows.) And this is the logic which triggers all smart radiators to shut off or resume to Auto EDIT: sorry I am an new user here and can only embed images. here is a link: [https://drive.proton.me/urls/VC3RPZD4X8#zLVYr5i6TkHI](https://drive.proton.me/urls/VC3RPZD4X8#zLVYr5i6TkHI) ---
**Author:** ![Wim\_Post](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wim_post/32/56793_2.png) [@Wim\_Post](https://community.homey.app/u/Wim_Post)\ **Post date:** [December 15, 2025, 10:31am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/2 "2025-12-15T10:31:09Z")
![Scherm­afbeelding 2025-12-15 om 11.24.05](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/4/f/4f02129d561d6cf4c35847db294910c5fde9c06a.png) In your first and third flow you have more then one triggers before an ‘ALL’-card. Like the top flow in the screenprint. This will never run. If one of the windows is opened, you will have to check the state of the other windows. Like the bottom flow. Maybe this will work for you: if at least one window of each room is opened then set variable ‘Stosslueften’ to YES. Imagine plafond 1 en 2 are windows in room 1 and plafond 3 en 4 in room 2: ![Scherm­afbeelding 2025-12-15 om 11.41.15](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/0/103120fbeac5875bc51187d526c9b595be907aa6.png) ---
**Author:** ![DirkG](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/dirkg/32/118897_2.png) [@DirkG](https://community.homey.app/u/DirkG)\ **Post date:** [December 15, 2025, 12:36pm UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/3 "2025-12-15T12:36:15Z")
@Simon_Kai, programmed a Homey Script that can indicate when it’s time to ventilate (Stoßlüften). To do this, temperature and humidity sensors are needed in the relevant rooms, as well as the current values from outside. Just a suggestion. > [@Perfekte Lüftungsempfehlung](https://community.homey.app/t/perfekte-luftungsempfehlung/115380): > > Hallo zusammen, ich möchte diesem Forum gerne etwas zurück geben, nachdem ich bereits so oft hier Hilfe und Unterstützung bekommen habe. Ich habe mich schon lange gefragt, wie eine gut und korrekte Lüftungsempfehlung aussehen kann. dabei bin ich über diese Seite gestolpert: [https://www.sarahandrobin.com/ingo/luftfeuchtigkeit.php](https://www.sarahandrobin.com/ingo/luftfeuchtigkeit.php) hier wird das Thema wirklich sehr umfassend behandelt und ein Rechner zu verfügung gestellt. Ich bin sehr dankbar, dass ich dieses nutzen durfte und hier auch teilen… ---
**Author:** ![Andreas\_Martin](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/andreas_martin/32/121367_2.png) [@Andreas\_Martin](https://community.homey.app/u/Andreas_Martin)\ **Post date:** [December 15, 2025, 9:35pm UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/4 "2025-12-15T21:35:46Z")
Thank you! Regarding that idea: I do have CO2 sensors, which are another variable or even a complete replacement except in the bathroom where a humidity sensor is preffered. After all: I don’t need that sophisticated calculation. Since we are proper germans (kidding) we do stosslüften daily at set times. So no need for notification. I just want a DETECTION of stosslüften to shut off all thermostats. I use tado X and have their subscription which includes an open window detection. It is okay but not 100% working all the times. Thats why I am looking for an advanced flow for detection. PS: buying additional sensors is not an issue if you guy recommend any. ---
**Author:** ![DirkG](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/dirkg/32/118897_2.png) [@DirkG](https://community.homey.app/u/DirkG)\ **Post date:** [December 17, 2025, 11:27am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/5 "2025-12-17T11:27:15Z")
> [@Andreas\_Martin](#): > > recommend any With, or without display? Which wireless standard do you prefer? ---
**Author:** ![Andreas\_Martin](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/andreas_martin/32/121367_2.png) [@Andreas\_Martin](https://community.homey.app/u/Andreas_Martin)\ **Post date:** [December 17, 2025, 12:19pm UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/6 "2025-12-17T12:19:08Z")
I am open to anything. I do have the homey pro so all standards should work. What do you have in mind? ---
**Author:** ![DirkG](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/dirkg/32/118897_2.png) [@DirkG](https://community.homey.app/u/DirkG)\ **Post date:** [December 18, 2025, 4:34pm UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/7 "2025-12-18T16:34:05Z")
> [@Andreas\_Martin](#): > > so all standards should work Theoretically, yes. However, there are very clear basic requirements for Zigbee and Z-Wave devices so that they work reliably and do not constantly lose connection. Bluetooth devices, for example, naturally have a limited range. In addition, Homey Bluetooth’s range is not that great. Bluetooth devices will probably only work in the same room where the Homey Pro is located. I just wanted to mention that. Currently, I have four [SONOFF SNZB-02D Zigbee LCD Smart Temperature Humidity Sensors](https://sonoff.tech/en-de/products/sonoff-snzb-02d-zigbee-lcd-smart-temperature-humidity-sensor?_pos=1&_psq=snzb-02&_ss=e&_v=1.0) in use and am quite happy with them. The display is easy to read and the response time is good. Regarding the battery life, I am unable to make any statements at this time. In addition, I have an [Aqara Temperature and Humidity Sensor (model WSDCGQ11LM)](https://www.aqara.com/en/product/temperature-humidity-sensor/) in use. It does what it’s supposed to do, but it doesn’t have a display. IKEA has released new smart home products with the Matter standard, including a temperature and humidity sensor for just 7,99€, called [TIMMERFLOTTE](https://www.ikea.com/de/en/p/timmerflotte-temperature-humidity-sensor-smart-30597606/). In my opinion, the interesting thing about this sensor is that it is powered by two AAA batteries. I assume that rechargeable batteries can also be used, as is the case with other devices. However, I have no personal experience with this sensor. ---
**Author:** ![Andreas\_Martin](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/andreas_martin/32/121367_2.png) [@Andreas\_Martin](https://community.homey.app/u/Andreas_Martin)\ **Post date:** [December 19, 2025, 10:01am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/8 "2025-12-19T10:01:05Z")
Yes to your post. I am looking for a sensor for stosslüften. I do have temperature and humidity sensors in most rooms… Maybe THIS is the lightbulb moment: Those temp and humidity can be the stosslueften sensors! Flow which measures dropping temperature in multiple rooms. (Caveat this only works during cold days. which should suffice for switching off the thermostats since they are only on during cold days) ---
**Author:** ![Andreas\_Martin](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/andreas_martin/32/121367_2.png) [@Andreas\_Martin](https://community.homey.app/u/Andreas_Martin)\ **Post date:** [December 20, 2025, 8:57am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/9 "2025-12-20T08:57:28Z")
Now the only issue is: HOW TO MEASURE relative temperature drops? I can only measure absolute drops. Is there a way to do it via a variable which homey writes constantly and measures the delta / difference? Appreciate you guys for helping me! ---
**Author:** ![Wim\_Post](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wim_post/32/56793_2.png) [@Wim\_Post](https://community.homey.app/u/Wim_Post)\ **Post date:** [December 20, 2025, 10:08am UTC](https://community.homey.app/t/multiple-room-ventilation-stosslueften/146943/10 "2025-12-20T10:08:39Z")
> **[Insight Trends Reloaded | Homey](https://homey.app/nl-nl/app/com.spkes.insightTrendsReloaded/Insight-Trends-Reloaded/)** > > Get more out of your Insights With the insight trends reloaded app you could determine a sudden temperature drop (in more than one room) But IMHO this will trigger to late: by the time it triggers it is time to close the windows again? Opening several windows means a lot of manual actions. So pushing one button (10 minutes before ?) to initiate ‘stosslüften’ seams very little effort to me.